The present invention relates generally to a system for manufacturing heat exchangers for air conditioning systems, which includes a device for manufacturing cylindrical header pipes through press forming of plates, a device for manufacturing V-shaped holders through roll forming of band plates, a device for manufacturing tubes by inserting into the holders inner fins obtained through press forming or roll forming, a device for manufacturing corrugated outer fins through cutting of band plates by a corrugating cutter, and a device for superimposing the inner fins and the outer fins on each other and assembling thereto the header pipes. The present invention relates particularly to the above tubes manufacturing device in particular. The present invention relates more particularly to a method and a system for manufacturing refrigerant tubes for condensers for use, e.g. in an automotive refrigerating cycle.
A refrigerant tube for condensers for use in an automotive refrigerating cycle is compressedly formed out of a metallic material with small weight and excellent thermal conductivity such as aluminum or aluminum alloy. The refrigerant tube includes therein a band-plate-like inner fin made of the same metallic material to excellently refrigerate a gaseous refrigerant circulating in the tube.
When manufacturing the refrigerant tube with inner fin, first, a holder serving as an outer shell of the tube is formed to have a compressed closed section, and then the inner fin is inserted into the holder from an opening arranged at one end thereof.
With the known refrigerant tube, however, since the band-plate-like inner fin is inserted into the holder having the compressed closed section from the opening at one end thereof, a difficulty arises when inserting an end of the inner fin into the opening of the holder. Moreover, even if insertion of the end of the inner fin into the opening of the holder is performed smoothly, the inner fin may be caught and bent at some midpoint of the holder, resulting in considerably degraded insertion workability.
Further, along with degraded insertion workability, a long insertion stroke of the inner fin deteriorates a productivity of the refrigerant tube.
It is, therefore, an object of the present invention to provide a method and a system for manufacturing refrigerant tubes for condensers, which enable an improvement in manufacturing yield and in productivity.
One aspect of the present invention lies in providing a method of manufacturing a refrigerant tube for a condenser, comprising the steps of:
forming an inner fin like a band plate having a predetermined length;
forming a holder having a substantially V-shaped open section and a predetermined length;
inserting said inner fin into said holder from a V-shaped opening of said holder; and
pressing said holder to close said V-shaped opening and change said substantially V-shaped open section to a compressed closed section, whereby said inner fin is fixed in said holder.
Another aspect of the present invention lies in providing a system for manufacturing a refrigerant tube for a condenser, comprising:
means for forming an inner fin like a band plate having a predetermined length;
means for forming a holder having a substantially V-shaped open section and a predetermined length;
means for horizontally transporting said inner fin held in a horizontal position in one direction;
means for horizontally transporting said holder with a V-shaped opening turned upward in the same direction as that of said inner fin to be located under said inner fin;
means for turning said inner fin from said horizontal position to a vertical position for insertion into said holder from said opening; and
means for pressing said holder to close said V-shaped opening and change said substantially V-shaped open section to a compressed closed section, whereby said inner fin is fixed in said holder.
Still another aspect of the present invention lies in providing a system for manufacturing a refrigerant tube for a condenser, comprising:
a first press forming machine forming an inner fin like a band plate having a predetermined length;
a roll forming machine forming a holder having a substantially V-shaped open section and a predetermined length;
a first conveyer connected to said first press forming machine, said first conveyer horizontally transporting said inner fin held in a horizontal position in one direction;
a second conveyer connected to said roll forming machine, said second conveyer horizontally transporting said holder with a V-shaped opening turned upward in the same direction as that of said inner fin to be located under said inner fin;
a turning unit arranged at a downstream end of said first conveyer, said turning unit turning said inner fin from said horizontal position to a vertical position for insertion into said holder from said opening; and
a second press forming machine arranged adjacent to said second conveyer, said second press forming machine pressing said holder to close said V-shaped opening and change said substantially V-shaped open section to a compressed closed section, whereby said inner fin is fixed in said holder.